Heat exchanger

ABSTRACT

A positioning protruding portion ( 86   b ) that protrudes toward a fluid side cup plate ( 81 ) side and is to be fitted into a positioning hole ( 81   a ) formed through the fluid side cup plate ( 81 ) is formed in a base plate ( 86 ) in a position opposite, in the stacking direction, fluid flow hole portions ( 80   b,    82   b ) formed in cup plates ( 80, 82 ) for introducing fluid (Fld) into a fluid flow layer ( 90 ) that contacts the base plate ( 86 ).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a vehicle heat exchanger that performs heat exchange between a first heat carrier and a second heat carrier that flow between stacked plates.

2. Description of Related Art

Published Japanese Translation of PCT application No. 2007-518958 (JP-A-2007-518958), Japanese Patent Application Publication No. 2000-310497 (JP-A-2000-310497), and Japanese Patent Application Publication No. 2000-283661 (JP-A-2000-283661), for example, all describe heat exchangers in which plates are stacked together. In JP-A-2007-518958, JP-A-2000-310497, and JP-A-2000-283661, various heat exchangers that improve heat exchanger safety, the ease of assembling a plurality of plates that form the heat exchanger, and the ability to ensure the rigidity of a plurality of plates and the like are proposed.

A stacked vehicle heat exchanger (such as a transmission fluid cooler) has also been proposed that has dish-shaped plates (i.e., a cup plates), of which the peripheral edge portions are fixed in a liquid-tight manner when stacked, formed such that a first layered space into which a first heat carrier (such as transmission fluid) is introduced and a second layered space into which a second heat carrier (such as coolant) is introduced, are formed alternately between them. This stacked vehicle heat exchanger performs heat exchange between the first heat carrier and the second heat carrier. This kind of vehicle heat exchanger is provided with a base plate that serves as a base when the cup plates are stacked together in order, for example. That is, in this kind of vehicle heat exchanger, cup plates are formed (i.e., assembled) stacked together in order on the base plate. At this time, in order to uniquely determine the relative position of the base plate and the cup plate that abuts against (i.e., is stacked directly on) this base plate, shapes for positioning, for example, must be provided on each. However, such shapes for positioning may affect the mountability to the vehicle. While it is possible to perform positioning by providing a recessed portion on one and a protruding portion on the other, these shapes may protrude outside of the vehicle heat exchanger, or if this is avoided, may conversely become protruding portions that protrude toward the layer side of the heat carrier and thus impede the flow of the heat carrier. In this way, there is room for innovation with respect to the positioning of the base plate and the cup plate. These issues are not well-known.

SUMMARY OF THE INVENTION

The invention provides a vehicle heat exchanger capable of improving mountability in a vehicle.

A first aspect of the invention relates to a vehicle heat exchanger. This vehicle heat exchanger includes a plurality of cup plates that are formed such that a first layered space into which a first heat carrier is introduced and a second layered space into which a second heat carrier is introduced are formed alternately between the plurality of cup plates when the plurality of plates are stacked, and in which peripheral end portions of the plurality of cup plates are fixed together in a liquid-tight manner; and a base plate that is thicker than the cup plates and on which the cup plates are stacked in order. The vehicle heat exchanger performs heat exchange between the first heat carrier and the second heat carrier. A positioning protruding portion that protrudes toward a side where there is an end cup plate that contacts the base plate and is to be fitted into a positioning hole for positioning the end cup plate with respect to the base plate, formed through the end cup plate, from among the stacked cup plates, is formed in the base plate in a position facing, in a stacking direction of the cup plates, a heat carrier flow hole portion provided in the plurality of cup plates for introducing the heat carrier into a layered space that contacts the base plate, from among the first layered space and the second layered space.

Accordingly, a positioning protruding portion that protrudes toward an end cup plate that contacts the base plate and is to be fitted into a positioning hole for positioning the end cup plate with respect to the base plate, formed through the end cup plate, from among the stacked cup plates, is formed in the base plate in a position opposite, in the stacking direction, a heat carrier flow hole portion provided in the plurality of cup plates for introducing the heat carrier into a layered space that contacts the base plate, from among the first layered space and the second layered space. As a result, the positioning hole formed in the end cup plate and the positioning protruding portion formed on the base plate make it possible to appropriately position the end cup plate and the base plate relative to one another, while avoiding a protruding shape that protrudes out to the outside, opposite the end cup plate side, of the base plate. Accordingly, the mountability (or the degree of freedom with regards to mounting) of the heat exchanger to the vehicle can be improved. In particular, the heat carrier flow hole portions formed on the cup plates other than the end cup plate are provided in positions opposite, in the stacking direction, the positioning hole formed in the end cup plate, i.e., the holes of the cup plates are provided in the same positions, so when the thicknesses of the cup plates that form the same layered spaces as that of the end cup plate are the same, these cup plates can be treated as common parts, which enables productivity to be improved.

The positioning protruding portion formed on the base plate may be formed in a shape that protrudes no more than a thickness of the end cup plate, toward a side where there is a layered space that contacts the base plate. Accordingly, the flow of a heat carrier introduced into the flow layer that contacts the base plate is impeded as little as possible, so cooling performance improves, compared to a case in which the positioning protruding portion is a shape that protrudes toward the side with the flow layer that contacts the base plate, or a case in which the positioning protruding portion is a shape that cuts through the layered space and abuts against the cup plate that is stacked on the base plate after the end cup plate in order to support that cup plate.

The end cup plate may be made thicker than the cup plates other than the end cup plate. Accordingly, positioning strength can be adequately ensured even if the shape for determining the relative position with respect to the base plate is a simple hole that has not been burred (i.e., formed with a cylindrical surface), for example.

A thickness of the end cup plate may be a predetermined thickness set in advance as a thickness that does not require an annular protrusion to be formed by burring at the positioning hole in order to ensure strength. Accordingly, positioning strength is able to be adequately ensured without forming an annular protrusion for positioning by burring on the end cup plate.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, advantages, and technical and industrial significance of exemplary embodiments of the invention will be described below with reference to the accompanying drawings, in which like numerals denote like elements, and wherein:

FIG. 1 is an example of a block diagram schematically showing the structure of a cooling system provided in a vehicle;

FIG. 2 is a sectional view of a heat exchanger shown in FIG. 1;

FIG. 3 is a sectional view of another heat exchanger to which the invention may be applied;

FIG. 4 is a sectional view of a reference example (related art) of a heat exchanger when another fluid side cup plate structure is employed as it is as an end fluid side cup plate; and

FIG. 5 is a sectional view of another reference example (other related art) of a heat exchanger.

DETAILED DESCRIPTION OF EMBODIMENTS

In the invention, the first heat carrier is preferably transmission fluid, the second heat carrier is preferably coolant, and the vehicle heat exchanger is preferably a transmission fluid cooler capable of cooling at least the transmission fluid.

Also, the transmission fluid is preferably hydraulic fluid (transmission fluid) that can be used in a vehicular automatic transmission, for example. More specifically, this hydraulic fluid may be, for example, well-known hydraulic fluid (ATF: Automatic Transmission Fluid) used in a planetary gear type automatic transmission or a synchronous mesh twin shaft parallel axis-type automatic transmission or the like, well-known hydraulic fluid (CVTF) used in a belt-type continuously variable transmission (belt-type CVT) or a traction-type continuously variable transmission or the like, well-known hydraulic fluid used in an automatic transmission for a hybrid vehicle that functions as a so-called electric continuously variable transmission that includes a differential mechanism and an electric motor, or well-known hydraulic fluid used in an automatic transmission mounted in a so-called parallel hybrid vehicle that includes an electric motor capable to transmitting power to an engine shaft and an output shaft or the like.

Also, the coolant is preferably coolant that can be used to cool an internal combustion engine such as a gasoline engine or a diesel engine, for example, and that is cooled by heat exchange being performed with the outside air by a well-known radiator.

Hereinafter, example embodiments of the invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram schematically showing the structure of a cooling system 20 provided in a vehicle 10. In FIG. 1, the cooling system 20 includes, for example, a radiator 30, a thermostat 40, a water pump 50, a heater core 60, and a vehicle heat exchanger (hereinafter, referred to as “heat exchanger”) 70 to which the invention may be applied. The solid arrows in FIG. 1 indicate the flow of coolant Clt, and the broken arrows indicate the flow of transmission fluid Fld (hereinafter, referred to as “fluid Fld”).

The radiator 30 receives coolant Clt for an engine 100 that flows out from an outlet 102 of a water jacket of the engine 100 mounted in the vehicle 10, cools the coolant Clt through heat exchange with outside air, and discharges the cooled coolant Clt out from an outlet 34 into an inlet 42 of the thermostat 40.

Until the coolant Clt becomes equal to or greater than a predetermined temperature, for example, the thermostat 40 closes a value on the inlet 42 side to prevent the coolant Clt from flowing from the inlet 42 to an outlet 44. On the other hand, when the coolant Clt becomes equal to or greater than the predetermined temperature, for example, the thermostat 40 opens the valve on the inlet 42 side to allow the coolant Clt to flow from the inlet 42 to the outlet 44, from which the coolant Clt then flows out to the water pump 50. Also, the thermostat 40 receives, from an inlet 46, coolant Clt that flows through a bypass flow path 104 in the water jacket of the engine 100, and channels this coolant Clt from the outlet 44 to the water pump 50. Also, the thermostat 40 receives, from an inlet 48, coolant Clt that flows through the heater core 60, and channels this coolant Clt from the outlet 44 to the water pump 50.

The water pump 50 is provided in the engine 100, for example, and draws in coolant Clt via the thermostat 40 and supplies it to the water jacket of the engine 100 that channels the coolant Clt to various parts.

The heater core 60 receives coolant Clt that flows out from an outlet 106 of the water jacket of the engine 100, and performs heat exchange between this coolant Clt and air, thereby generating warm air.

The heat exchanger 70 includes a coolant inlet 72 that receives coolant Clt that flows out from an outlet 108 of the water jacket of the engine 100, a coolant outlet 74 that channels the coolant Clt to the heater core 60 after it flows through the inside of the heat exchanger 70 itself, a fluid inlet 76 that receives fluid Fld that flows out from a vehicular automatic transmission (hereinafter, referred to as “automatic transmission”) 110, and a fluid outlet 78 that channels this fluid Fld to the automatic transmission 110 after it flows though the inside of the heat exchanger 70 itself. The heat exchanger 70 structured in this way performs heat exchange between the fluid Fld that serves as a first heat carrier that is received from the fluid inlet 76, and the coolant Clt that serves as a second heat carrier that is received from the coolant inlet 72.

With the cooling system 20 structured in this way, the coolant Clt that flows out from the water jacket of the engine 100, for example, is returned to the water jacket by the water pump 50 through the heater core 60 and the heat exchanger 70. Also, for example, when the valve of the thermostat 40 is closed, the coolant Clt that flows out from the water jacket of the engine 100 flows through the bypass flow path 104 and is returned to the water jacket by the water pump 50. In addition, for example, when the valve of the thermostat 40 is open, the coolant Clt that flows out from the water jacket of the engine 100 flows through the radiator 30 and is returned to the water jacket by the water pump 50.

Also, in the heat exchanger 70, for example, when it is cold (during warm-up), heat is transferred from coolant Clt that has been warmed by the engine 100 to the fluid Fld, so that the fluid Fld is warmed quickly, which in turn promotes warm-up of the automatic transmission 110, thereby improving fuel efficiency. On the other hand, after warm-up, heat is transferred to the coolant Clt from the fluid Fld that has been warmed by the automatic transmission 110, so the fluid Fld is cooled, and thus, the automatic transmission 110 is cooled.

FIG. 2 is a sectional view of the heat exchanger 70. In FIG. 2, the heat exchanger 70 includes, in addition to the coolant inlet 72, the coolant outlet 74, the fluid inlet 76, and the fluid outlet 78 described above, fluid side cup plates 80 that serve as first cup plates, coolant side cup plates 82 that serve as second cup plates, a base plate 86 that serves as an end plate that abuts against a cup plate (for example, a fluid side cup plate 80) on one side in the stacking direction of a core main body 84 formed by a stack of fluid side cup plates 80 and coolant side cup plates 82, and a top plate 88 that serves as an end plate that abuts against a cup plate (for example, a coolant side cup plate 82) on the other side in the stacking direction of the core main body 84. The fluid side cup plates 80, the coolant side cup plates 82, and the top plate 88 are each formed by a thin metal plate. Also, the base plate 86 is a thick metal plate (for example, an aluminum plate that is sufficiently thicker than the fluid side cup plates 80) that serves as the base when the fluid side cup plates 80 and the coolant side cup plates 82 are stacked in order. This base plate 86 functions as a strengthening member for mounting the heat exchanger 70 to the vehicle 10 (for example, to the automatic transmission 110). In FIG. 2, for the sake of convenience, the cross-section passing through the center of the coolant inlet 72 and the cross-section passing through the center of the fluid inlet 76 are shown on the same plane. Also, the coolant outlet 74 and the fluid outlet 78 are of course provided on the surface of the top plate 88, just like the coolant inlet 72 and the fluid inlet 76.

In the fluid side cup plates 80, coolant flow hole portions 80 a that allow the coolant Clt to flow and correspond to the coolant inlet 72 and the coolant outlet 74, and fluid flow hole portions 80 b that allow the fluid Fld to flow and correspond to the fluid inlet 76 and the fluid outlet 78, are formed in an aluminum plate that is approximately 0.2 mm to 0.5 mm thick, for example, by press-forming. Also, in the coolant side cup plates 82, coolant flow hole portions 82 a that allow the coolant Clt to flow and correspond to the coolant inlet 72 and the coolant outlet 74, and fluid flow hole portions 82 b that allow the fluid Fld to flow and correspond to the fluid inlet 76 and the fluid outlet 78, are formed in an aluminum plate that is approximately 0.2 mm to 0.5 mm thick, for example, by press-forming.

Also, the plurality of fluid side cup plates 80 and coolant side cup plates 82 are formed (i.e., assembled) in a stacked manner such that fluid flow layered spaces (hereinafter, referred to as “fluid flow layers”) 90 that serve as first layered spaces into which the fluid Fld is introduced, and coolant flow layered spaces (hereinafter, referred to as “coolant flow layers”) 92 that serve as second layered spaces into which the coolant Clt is introduced, are formed alternately between them. The plurality of fluid side cup plates 80 and coolant side cup plates 82 are fixed together in a liquid-tight manner at their peripheral edge portions by brazing. That is, the fluid side cup plates 80 form the fluid flow layers 90 and the coolant side cup plates 82 form the coolant flow layers 92, by the fluid side cup plates 80 and the fluid flow layers 90 being alternately stacked together. The fluid flow layers 90 are also flow paths (i.e., passages) for the fluid Fld, and the coolant flow layers 92 are also flow paths for the coolant Clt, so the heat exchanger 70 is a stacked vehicle heat exchanger that performs heat exchange between the fluid Fld in the fluid flow layers 90 and the coolant Clt in the coolant flow layers 92.

Inner fins 94 that serve as fins that abut against the fluid side cup plates 80 and the coolant side cup plates 82 are provided across the entire fluid flow layers 90, inside the fluid flow layers 90. Also, a plurality of individual convex protrusions 96 that protrude out toward the coolant flow layers 92 and abut against the fluid side cup plates 80 are formed at approximately equal density, for example, on the coolant side cup plates 82. The inner fins 94 and the convex protrusions 96 are both provided to improve heat-transfer performance during heat exchange performed between the fluid FM and the coolant Clt. In this way, the inner fins 94 and the convex protrusions 96 are both structures that perform heat exchange between the fluid Fld and the coolant Clt, but their structures for performing heat exchange are different with the fluid side cup plates 80 and the coolant side cup plates 82. In addition, the fluid side cup plates 80 and the coolant side cup plates 82 are both formed with thin metal plates, so the inner fins 94 and the convex protrusions 96 are both provided to ensure strength with respect to a load in the stacking direction in particular. The convex protrusions 96 are formed by press-forming the coolant side cup plates 82, for example. In other words, the convex protrusions 96 are depressions (i.e., dimples) formed by press-forming the coolant side cup plates 82.

Therefore, in the heat exchanger 70 of this example embodiment, the structure of the convex protrusions 96 is used and the structure of the inner fins 94 is not used, on the coolant side cup plates 82 (in the coolant flow layers 92). Therefore, the height of the convex protrusions 96 (i.e., the dimension of the amount that the convex protrusions 96 protrude out in the stacking direction from the surface of the flat portion on the coolant flow layer 92 side of the coolant side cup plates 82) that corresponds to the thickness dimension in the stacking direction of the coolant flow layers 92 is set to a smaller value than the height in the stacking direction of the inner fins 94 that corresponds to the thickness dimension in the stacking direction of the fluid flow layers 90. For example, the height of the convex protrusions 96 (i.e., the thickness of the coolant flow layers 92) is obtained through testing (or by design) in advance and set taking into account the number and formation positions of the convex protrusions 96, and the heat balance between the fluid side heat release amount Qf and the coolant side heat release amount Qc.

As described above, the fluid flow layers 90 and the coolant flow layers 92 are set to thicknesses with different thickness dimensions in the stacking direction. Also, the shape of the fluid side cup plates 80 and the shape of the coolant side cup plates 82 are formed different from each other, such that fluid flow layers 90 and coolant flow layers 92 of different thicknesses are formed (matching each of the different thicknesses, for example). For example, flange portions formed on the coolant flow hole portions 80 a of the fluid side cup plates 80 and on the fluid flow hole portions 82 b of the coolant side cup plates 82, respectively, protrude in the stacking direction corresponding to the fluid flow layers 90 and the coolant flow layers 92, respectively, that have different thicknesses. Also, outer wall portions 80 c of the fluid side cup plates 80 and outer wall portions 82 c of the coolant side cup plates 82 protrude out in the stacking direction corresponding to the fluid flow layers 90 and the coolant flow layers 92, respectively, that have different thicknesses, while also protruding out the same amount in the stacking direction corresponding to the liquid-tight brazing between the plates when stacked.

In the heat exchanger 70, with the base plate 86 as the lowest level, the core main body 84 is formed by stacking the fluid side cup plate 80, the inner fins 94, the coolant side cup plate 82, the fluid side cup plate 80, and the inner fins 94, . . . in this order from the base plate 86 upward, and the top plate 88 is stacked on top as the highest level. Also, the heat exchanger 70 is manufactured by brazing these together in a liquid-tight manner in a brazing furnace, for example, and then a complete inspection is performed after manufacturing (for example, an inspection is performed for fluid Fld and coolant Clt leaks).

Here, the coolant flow hole portions 80 a, the fluid flow hole portions 80 b, the coolant flow hole portions 82 a, and the fluid flow hole portions 82 b are formed in predetermined shapes that enable the stacked plates to be brazed together in a liquid-tight manner, while serving as positioning holes when alternately stacking the fluid side cup plates 80 and the coolant side cup plates 82 together. For example, annular protrusions that are the inner peripheral edges of the fluid flow hole portions 80 b and are burred (i.e., formed with a cylindrical surface) so as to protrude out toward the coolant side cup plate 82 side are brazed in a liquid-tight manner while fit into the fluid flow hole portions 82 b on which flange portions that protrude out toward the fluid side cup plate 80 side are formed. Also, annular protrusions that are the inner peripheral edges of the coolant flow hole portions 82 a and are burred so as to protrude out toward the fluid side cup plate 80 side are brazed in a liquid-tight manner while fit into the coolant flow hole portions 80 a on which flange portions that protrude out toward the coolant side cup plate 82 side are formed.

In order to uniquely determine the relative positions of the base plate 86 and the end fluid side cup plate 80 that is contacting the base plate 86, from among the stacked cup plates, (hereinafter, the end fluid side cup plate 80 that contacts the base plate 86 will be referred to as “fluid side cup plate 81”) when the fluid side cup plates 80 and the coolant side cup plates 82 are stacked in order on the base plate 86, a shape for positioning must be provided on each of the plates. FIG. 4 is a sectional view of a reference example (related art) of a heat exchanger 170 when a fluid side cup plate 80 is employed as it is as an end fluid side cup plate. In FIG. 4, the fluid flow hole portions 80 b also serve as positioning holes when stacking the fluid side cup plates 80 onto the base plate 86. Therefore, a positioning recessed portion 86 a corresponding to annular protrusions 80 b 1 that are burred on the fluid flow hole portions 80 b and protrude toward the base plate 86 side is formed by press-forming, for example, on the base plate 86, such that the annular protrusion 80 b 1 will fit into the base plate 86. As a result, a protrusion toward the outside, opposite the fluid side cup plate 80 side, is produced on the positioning recessed portion 86 a, which may affect the mountability of the heat exchanger 170 to the vehicle 10 (e.g., the automatic transmission 110). In other words, the degree of freedom when mounting the heat exchanger 170 to the vehicle 10 may decrease. It should be noted that the annular protrusions 80 b 1 must be formed to ensure positioning strength with the fluid side cup plates 80 that are formed with thin metal plates. From another perspective, forming the annular protrusions 80 b 1 by burring on the fluid flow hole portions 80 b enables the fluid side cup plates 80 to be made as thin as possible. It is also possible to have the annular protrusions 80 b 1 protrude toward the fluid flow layer 90 side, but in this case, they may impede the flow of fluid Fld inside the fluid flow layers 90.

Therefore, with the heat exchanger 70 according to this example embodiment, as shown in FIG. 2, the fluid side cup plate 81 is made thicker than the fluid side cup plates 80 other than the fluid side cup plate 81, and a positioning hole 81 a for determining the relative position with respect to the base plate 86 is formed through this fluid side cup plate 81. The thickness of the fluid side cup plate 81 is a predetermined thickness of approximately 1 mm, for example, set in advance as a thickness at which it is not necessary to form an annular protrusion (such as the annular protrusions 80 b 1) by burring at a positioning hole 81 a that extends through to ensure positioning strength, for example. That is, the thickness of the fluid side cup plate 81 is a predetermined thickness set in advance to adequately ensure positioning strength, even if the positioning hole 81 a for determining the relative position with the base plate 86 is a simple hole (i.e., a drainage hole) that has not been burred.

Also, a positioning protruding portion 86 b that protrudes toward the fluid side cup plate 81 side and is to be fitted into the positioning hole 81 a formed through the fluid side cup plate 81 is formed by press-forming, for example, so as to be able to fit into the positioning hole 81 a when the fluid side cup plate 81 is stacked onto the base plate 86. That is, the positioning protruding portion 86 b that protrudes toward the fluid side cup plate 81 side and is to be fitted into the positioning hole 81 a formed through the fluid side cup plate 81, is formed in the base plate 86 in a position opposite, in the stacking direction, the fluid flow hole portions 80 b and 82 b formed in the cup plates 80 and 82, respectively, for introducing fluid Fld into the fluid flow layer 90 that contacts the base plate 86. In this way, the fluid flow hole portions 80 b and the positioning hole 81 a are provided in the same positions in the fluid side cup plates 80 and 81, so if the thicknesses of the fluid side cup plates 80 and 81 are the same, the fluid side cup plates 80 and 81 can be common parts. Also, this positioning recessed portion 86 a has a flat shape that protrudes corresponding to the positioning hole 81 a, for example, and the height of the protruding portion, is set to a predetermined height (for example, a height of approximately the same as or less than the thickness of the fluid side cup plate 81) that is set in advance and that enables the fluid side cup plate 81 and the base plate 86 to be appropriately positioned, for example. Therefore, in the fluid flow layer 90 formed by the fluid side cup plate 81, the protruding portion 86 b will not protrude toward the fluid flow layer 90 side more than the thickness of the positioning hole 81 a at the positioning hole 81 a portion, so the flow of fluid Fld will be impeded as little as possible. In this way, with the heat exchanger 70 of this example embodiment, making the fluid side cup plate 81 thicker than the other fluid side cup plates 80 obviates the need for the annular protrusion formed by burring at the positioning hole 81 a for positioning the fluid side cup plates on the base plate 86. Also, on the base plate 86, the shape for positioning may be changed from an inner recessed shape (see the positioning recessed portion 86 a) to an inner protruding shape (see the positioning protruding portion 86 b). This makes it possible to prevent (i.e., avoid) protrusions protruding toward the outside from the base plate 86.

As described above, according to this example embodiment, the positioning protruding portion 86 b that protrudes toward the fluid side cup plate 81 side and is to be fitted into the positioning hole 81 a formed through the fluid side cup plate 81 is formed in the base plate 86 in a position opposite, in the stacking direction, the fluid flow hole portions 80 b and 82 b formed in the cup plates 80 and 82, respectively for introducing fluid Fld into the fluid flow layer 90 that contacts the base plate 86. As a result, the positioning hole 81 a formed in the fluid side cup plate 81 and the positioning protruding portion 86 b formed on the base plate 86 make it possible to appropriately position the fluid side cup plate 81 and the base plate 86 relative to one another, while avoiding a protruding shape that protrudes out to the outside, opposite the fluid side cup plate 81 side, of the base plate 86. Accordingly, a protrusion toward the outside from the base plate 86 can be prevented, i.e., there is no longer an outer protruding shape on the base plate 86, so the mountability of the heat exchanger 70 to the vehicle 10 (i.e., the automatic transmission 110) (or the degree of freedom when mounting the heat exchanger 70 to the vehicle 10) can be improved. In particular, the fluid flow hole portions 80 b and 82 b formed on the fluid side cup plates 80 and 82 are provided in positions opposite, in the stacking direction, the positioning hole 81 a formed in the fluid side cup plate 81, i.e., the fluid flow hole portions 80 b and the positioning hole 81 a are provided in the same positions on the fluid side cup plates 80 and 81, respectively, so when the thicknesses of the fluid side cup plates 80 and 81 are the same, the fluid side cup plates 80 and 81 can be treated as common parts, which enables productivity to be improved.

Also, according to this example embodiment, the positioning protruding portion 86 b formed on the base plate 86 is formed in a shape that does not protrude toward the side with the fluid flow layer 90 that contacts the base plate 86 more than the thickness of the fluid side cup plate 81 (i.e., the thickness of the positioning hole 81 a formed in the fluid side cup plate 81). Therefore, the flow of fluid Fld introduced into the fluid flow layer 90 that contacts the base plate 86 is impeded as little as possible, so cooling performance improves, compared to, for example, a case in which the positioning protruding portion 86 b is a shape that protrudes toward the side with the fluid flow layer 90 that contacts the base plate 86, or a case in which the positioning protruding portion 86 b is not formed in a position opposite the fluid flow hole portions 80 b and 82 b in the stacking direction and is shaped so as to cut through the fluid flow layer 90 that contacts the base plate 86 and abut against the coolant side cup plate 82 in order to support this coolant side cup plate 82.

Also in this example embodiment, the fluid side cup plate 81 is formed thicker than the fluid side cup plates 80 other than from the fluid side cup plate 81. Therefore, positioning strength can be adequately ensured even if the shape for determining the relative position with respect to the base plate 86 is a simple hole that has not been burred, for example.

Also in this example embodiment, the thickness of the fluid side cup plate 81 is a predetermined thickness set in advance as a thickness that does not require the annular protrusion 80 b 1 to be formed by burring at the positioning hole 81 a in order ensure positioning strength. As a result, positioning strength can be adequately ensured without forming the annular protrusion 80 b 1 for positioning by burring on the fluid side cup plate 81.

Next, another example embodiment of the invention will be described. Portions in the description below that are common to the example embodiment described above will be denoted by like reference characters and descriptions of those portions will be omitted.

FIG. 3 is a sectional view of a heat exchanger 200 to which the invention may be applied, according to another example embodiment that is different from the example embodiment with the heat exchanger 70 described above. In FIG. 3, the heat exchanger 200 includes fluid side cup plates 206 and coolant side cup plates 208 that are stacked together, with their peripheral edge portions fixed in a liquid-tight manner by brazing, between a base plate 202 and a top plate 204, such that fluid flow layers 210 and coolant flow layers 212 are alternately formed between them. That is, the fluid side cup plates 206 form the fluid flow layers 210 and the coolant side cup plates 208 form the coolant flow layers 212, by the fluid side cup plates 206 and the coolant side cup plates 208 being alternately stacked together. Also, just like the heat exchanger 70 described above, the heat exchanger 200 is a stacked vehicle heat exchanger that performs heat exchange between the fluid Fld in the fluid flow layers 210 and the coolant Clt in the coolant flow layers 212. In the heat exchanger 200, inner fins 214 that abut against the fluid side cup plates 206 and the coolant side cup plates 208 are provided both inside the fluid flow layers 210 and inside the coolant flow layers 212.

Coolant flow hole portions 206 a that allow the coolant Clt to flow and correspond to a coolant inlet 216 and a coolant outlet, not shown, and fluid flow hole portions 206 b that allow the fluid Fld to flow and correspond to a fluid inlet 218 and a fluid outlet, also not shown, are formed in the fluid side cup plates 206. Also, coolant flow hole portions 208 a that allow the coolant Clt to flow and correspond to the coolant inlet 216 and the coolant outlet, not shown, and fluid flow hole portions 208 b that allow the fluid Fld to flow and correspond to the fluid inlet 218 and the fluid outlet, not shown, are formed in the coolant side cup plates 208.

In the heat exchanger 200, with the base plate 202 as the lowest level, the core main body 220 is formed by stacking the inner fins 214, the fluid side cup plate 206, the inner fins 214, the coolant side cup plate 208, the inner fins 94, the fluid side cup plate 206, . . . in this order from the base plate 202 upward, and stacking the top plate 204 on top as the highest level. Also, the heat exchanger 200 is manufactured by brazing these together in a liquid-tight manner in a brazing furnace, for example, and then a complete inspection is performed after manufacturing (for example, an inspection is performed for fluid Fld and coolant Clt leaks).

Here, the coolant flow hole portions 206 a, the fluid flow hole portions 206 b, the coolant flow hole portions 208 a, and the fluid flow hole portions 208 b are formed in a predetermined shapes that enable the stacked plates to be brazed together in a liquid-tight manner, while serving as positioning holes when alternately stacking the fluid side cup plates 206 and the coolant side cup plates 208 together.

Just as with the example embodiment described above, it is necessary to provide shapes for positioning on each of the plates in order to uniquely determine the relative positions of the base plate 202 and the end fluid side cup plate 206 that abuts against the base plate 202 (hereinafter this end fluid side cup plate will be referred to as “fluid side cup plate 207”). FIG. 5 is a sectional view of another reference example (other related art) of a heat exchanger 300 in which a fluid side cup plate 206 is employed as it is as an end fluid side cup plate, just like the heat exchanger 170 shown in FIG. 4.

In FIG. 5, the coolant flow hole portions 206 a are made to function as positioning holes when stacking the fluid side cup plates 206 onto the base plate 202. Therefore, a positioning recessed portion 202 a corresponding to annular protrusions 206 a 1 that are burred on the coolant flow hole portions 206 a and protrude toward the base plate 202 side is formed by press-forming, for example, on the base plate 202, such that the annular protrusion 206 a 1 will fit into the base plate 202. As a result, a protrusion toward the outside, opposite the fluid side cup plate 206 side, is produced on the positioning recessed portion 202 a of the base plate 202, which may affect the mountability of the heat exchanger 300 to the vehicle 10 (e.g., the automatic transmission 110).

Therefore, with the heat exchanger 200 of this example embodiment, just as with the heat exchanger 70 of the example embodiment described above, the fluid side cup plate 207 is made to be thicker than the fluid side cup plates 206 other than the fluid side cup plate 207, and a positioning hole 207 a for determining the relative position with respect to the base plate 202 is formed, as shown in FIG. 3. Also, a positioning protruding portion 202 b that protrudes toward the fluid side cup plate 207 side and is to be fitted into the positioning hole 207 a formed in the fluid side cup plate 207, is formed by press-forming, for example, on the base plate 202 so as to be able to fit into the positioning hole 207 a when the fluid side cup plate 207 is stacked onto the base plate 202. That is, the positioning protruding portion 202 b that protrudes toward the fluid side cup plate 207 side and is to be fitted into the positioning hole 207 a formed through the fluid side cup plate 207, is formed in the base plate 202 in a position opposite, in the stacking direction, the coolant flow hole portions 206 a and 208 a formed in the cup plates 206 and 208, respectively, for introducing coolant Clt into the coolant flow layer 212 that contacts the base plate 202. In this way, with the heat exchanger 200 of this example embodiment, the coolant flow hole portions 206 a and the positioning hole 207 a are provided in the same positions in the fluid side cup plates 206 and 207, so if the thicknesses of the fluid side cup plates 206 and 207 are the same, the fluid side cup plates 206 and 207 can be common parts. Also, making the fluid side cup plate 207 thicker than the other fluid side cup plates 206 obviates the need for the annular protrusion formed by burring at the positioning hole 207 a for positioning the fluid side cup plates on the base plate 202. Also, on the base plate 202, the shape for positioning may be changed from an inner recessed shape (see the positioning recessed portion 202 a) to an inner protruding shape (see the positioning protruding portion 202 b). This makes it possible to prevent (i.e., avoid) protrusions protruding toward the outside from the flat portion of the base plate 202.

As described above, according to this example embodiment, with the heat exchanger 200, the positioning protruding portion 202 b that protrudes toward the fluid side cup plate 207 side and is to be fitted into the positioning hole 207 a formed through the fluid side cup plate 207 is formed in the base plate 202 in a position opposite, in the stacking direction, the coolant flow hole portions 206 a and 208 a formed in the cup plates 206 and 208, respectively for introducing coolant Clt into the coolant flow layer 212 that contacts the base plate 202. As a result, similar effects as those obtained with the example embodiment described above are obtained.

Heretofore, example embodiments of the invention have been described in detail with reference to the drawings, but the invention may also be applied in other modes.

For example, in the example embodiment described, above, the heat exchangers 70 and 200 are transmission fluid heat exchangers that perform heat exchange between the fluid Fld and the coolant Clt, but the invention is not limited to this. That is, the invention may be applied to any stacked vehicle heat exchanger capable of performing heat exchange between a first heat carrier and a second heat carrier. For example, the invention may also be applied to a stacked vehicle heat exchanger in which the first heat carrier is the coolant Clt and the second heat carrier is the fluid Fld, or a stacked vehicle heat exchanger in which the first heat carrier is coolant (or engine oil) and the second heat carrier is engine oil (or coolant), or the like.

Also, in the example embodiment described above, the fluid side cup plates 81 and 207 are made thicker than the fluid side cup plates 80 and 206, but the invention is not limited to this. For example, the fluid side cup plates 81 and 207 may also be the same thickness as the fluid side cup plates 80 and 206. That is, the thickness of the fluid side cup plates 81 and 207 need only be a predetermined thickness that at least adequately ensures positioning strength, even if the positioning holes 81 a and 207 a are simple holes.

While the invention has been described with reference to example embodiments thereof, it is to be understood that the invention is not limited to the described embodiments or constructions. To the contrary, the invention is intended to cover various modifications and equivalent arrangements. In addition, while the various elements of the example embodiments are shown in various combinations and configurations, other combinations and configurations, including more, less or only a single element, are also within the scope of the invention. 

1. A vehicle heat exchanger comprising: a plurality of cup plates arranged such that a first layered space into which a first heat carrier is introduced and a second layered space into which a second heat carrier is introduced are defined alternately between the plurality of cup plates when the plurality of cup plates are stacked, and in which peripheral end portions of the plurality of cup plates are fixed together in a liquid-tight manner; and a base plate that is thicker than the cup plates and on which the cup plates are stacked in order, wherein the vehicle heat exchanger performs heat exchange between the first heat carrier and the second heat carrier; the plurality of cup plates is provided with a heat carrier flow hole portion to introduce the heat carrier into one of the first layered space and the second layered space; the one of the first layered space and the second layered space contacts the base plate; the base plate includes a positioning protruding portion; the positioning protruding portion is arranged in a position facing the heat carrier flow hole portion, in a stacking direction of the cup plates; the base plate contacts an end cup plate that is one of the stacked cup plates and through which a positioning hole is provided; and the positioning protruding portion protrudes toward an end cup plate side and is fitted into the positioning hole to position the end cup plate with respect to the base plate.
 2. The vehicle heat exchanger according to claim 1, wherein the positioning protruding portion provided on the base plate has in a shape that protrudes no more than a thickness of the end cup plate, toward a side where there is the layered space that contacts the base plate.
 3. The vehicle heat exchanger according to claim 1, wherein the end cup plate is thicker than the cup plates other than the end cup plate.
 4. The vehicle heat exchanger according to claim 1, wherein a thickness of the end cup plate is a predetermined thickness set in advance as a thickness that does not require an annular protrusion to be formed by burring at the positioning hole in order to ensure strength. 